Born and raised in the churchgoing Northern Ireland of the 1950s, Alister McGrath was educated at Belfast’s Methodist College. Today he is a writer on Christian thought and an outspoken critic of atheist scientist Richard Dawkins. It is easy to imagine that his journey from Christian background to Christian spotlight was straightforward. Easy, but wrong.

‘As a child I never had any interest in Christianity,’ he says. ‘I went through the motions of going to church with my parents but neither my heart nor my head was in it. It was while I was at the Methodist College, probably aged around 15 or 16, that I became an atheist – somebody who deliberately and intentionally does not believe in God and thinks that anyone who does believe in God is mentally deficient or seriously screwed up.

‘Growing up amid sectarian violence, I concluded that if there were no religion, there wouldn’t be any violence. At the time Marxism, with its offer of political transformation and its aim of doing away with religion, was very attractive to me. I was also studying natural sciences. To me, science had disproved God. So I was a Marxist atheist who enjoyed sciences.’

Such an idealistic stance lasted beyond schooldays. Alister went to Oxford University to study chemistry.

‘I was still a convinced atheist but I started to have one or two questions, such as: ‘If atheism was right, then why were so many people religious believers?’ I told myself it was because they were fools. Part of me was very happy with that answer but part of me knew that actually it wasn’t good enough. Then I discovered some very articulate Christians at the university. They showed me that atheism was not as robust as I had thought.

‘I began to realise that I’d misunderstood what Christianity was. I had thought that it was simply a kind of ritualistic, mechanistic thing. All about keeping rules. I had no idea that it was really about a personal relationship with Christ.

‘Discovering that changed things in a very big way. I discovered not simply that Christianity was true, but also that it was real. It was not just something that made sense but also something that could transform someone’s life. I decided I wanted to become a Christian.

‘I can’t point to a single defining moment but when I went to Oxford in the October I was an atheist; when I went home for Christmas I was a Christian.’

Alister is not one who believes that being a Christian means having to commit intellectual suicide. A first-class honours degree in chemistry was followed by a doctorate in molecular biophysics. He then gained a first in theology. He studied for the Anglican priesthood, was ordained and subsequently became a (non-honorary) doctor of divinity at Oxford.

As a scientist-theologian Professor McGrath spans the intellectual divide between disciplines which are often seen to be in conflict. Are science and religion, specifically Christianity, mutually excluding?

‘No, they’re not. In fact, many Christians who are scientists would say they find that these two disciplines reinforce each other. There’s a very strong religious motivation for scientific research. If you believe that God made the world, you can get additional insights into God by studying nature.

‘Science can’t answer the big questions such as ‘Why are we here?’ or ‘What’s life all about?’ In many respects science is raising these questions but not answering them. Therefore it’s essential for a theological narrative of things to run alongside the scientific account. Science and Christianity reinforce and complement each other.’

So science is not necessarily atheistic?

‘Science is neutral. It does not presuppose or imply atheism. Darwin’s theory of evolution, for example, is not by definition atheistic. Some people just interpret it that way.

‘A basic assumption in science is that we do not presume God. But science does not in principle exclude God. Science simply says we are not going to bring God into things as a matter of principle. Therefore someone can interpret the sciences in an atheistic way or a Christian way.

‘Richard Dawkins asserts very strongly that to buy into modern science is to say that there is no God. But that is simply not true – scientifically or philosophically. There are a large number of Christians who are scientists who spend most of their professional careers disproving him on this point.’

Evolutionary scientist Richard Dawkins is someone Alister has had under the microscope for a number of years. In 2004 Alister published Dawkins’ God, in which (in the style of gamekeeper-turned-poacher) he attacked Dawkins’s atheistic world view. The Dawkins Delusion? (due for publication this month) is his response to Dawkins’s bestselling The God Delusion. What makes him want to challenge his Oxford colleague?

‘Dawkins scores points by misrepresentation – by presenting arguments in their worst possible light and by choosing extreme Christians as though they are representative of mainstream Christianity.

‘He works on the assumption that his readers know very little about Christianity. He argues, for example, that God is a child abuser who encourages infanticide. He asserts that if you believe in evolution, you cannot believe in God, because evolution is by definition atheistic. But that is a very inaccurate interpretation.

‘Dawkins also interprets a Christian’s ‘faith’ as ‘blind trust’. To him ‘faith’ means running away from evidence. But that’s not a Christian definition of faith. Christians will say that faith is about believing in a God who not only exists but who may also be relied upon utterly, someone into whose hands I can entrust myself knowing that he’s going to guard me and keep me.

‘People like simple answers to hard questions. That’s why Dawkins is so popular. When I was an atheist I sounded like Richard Dawkins. I focused only on the things that fitted my theory. One of the things that made me stop being an atheist was realising that things are rather more complicated.’

Science, then, does not have all the answers. So what insights can Christianity give to seemingly insoluble questions, such as: Why does God allow suffering?

‘I don’t think we’re ever going to explain suffering completely. Christianity doesn’t offer us a neat theory of suffering. It speaks to us of a God who is present in suffering. In other words, when we suffer we don’t suffer on our own. Psalm 23, for example, says that even in the valley of the shadow of death God is with me.

‘How did God redeem the world? Through suffering – the suffering of Christ, his Son. It was a suffering that one day will bring about the complete elimination of suffering from the world. There are no easy explanations but there is this reassurance of a God who has been through suffering and will be with us as we suffer.

‘The fact that we find suffering so distressing is actually saying something very significant as if there is something built within us that says: ‘This isn’t right.’ I believe this instinct comes from God. And it’s saying that things won’t be like this for ever, one day it will be changed. There is more to life than the physical world and God urges us to find it.’

What can rationalistic science add to the idea of miracles?

‘It is commonly said that science disproves miracles. It doesn’t. Science says that there are certain things that by their nature are very improbable. So improbable, in fact, they shouldn’t happen at all. Science can’t say things can’t happen, merely that they are very improbable.

‘For the Christian, miracles seem to have this tendency to happen around Jesus. For the Christian, therefore, modern science makes these events all the more remarkable and it forces us to ask the question: ‘What is so significant about this man who does all these things?’

‘Science does not disprove the resurrection of Jesus. It says that the Resurrection cannot be explained by a natural process. The question is not so much ‘How did the Resurrection happen?’ but ‘What does it mean?’‘

Physicist Isaac Newton pictured God as a watchmaker, with the world running strictly to predetermined patterns. His cause-and-effect physics has been enhanced by chaos, quantum and relativity theories. How does Alister see God? A watchmaker, winding creation up and letting it go? A puppeteer, pulling the strings and putting words in people’s mouths?

‘I don’t believe we are simply puppets whom God manipulates. Nor is God someone who leaves us to our own devices. God is one who guides. He shows us the path to take but expects us to make the decision whether or not to take it.

‘One of the most astonishing things about the Christian gospel is that even when we take a wrong path God is still able to use us. God wants the best for us, he tries to guide us back on to the right track, but he doesn’t impose on us – he doesn’t deny us our responsibility.’

One area of contemporary scientific theory speaks of the possibility of gathering life into one formula – the theory of everything. Will that ever happen or is it a scientific Holy Grail?

‘Stephen Hawking says it is unattainable,’ says Alister. ‘But I think it’s worth attaining because if you believe God made the world, it means that there is some intrinsic rationality to the world which reflects the wisdom and the justice of God.

‘The theory of everything says there is one big thing that explains everything. One place where the buck stops. But that’s exactly what Christians have been saying about God: the buck stops with him. God can explain but does not need to be explained.

‘The theory of everything – the method of making sense of the world, the theories that we know – could simply be an explication of the mind of God.’